Answer to Question #134432 in General Chemistry for ashish

Question

explain different methods of synthesis of petrol

Answer 1

1. synthetic petrol

Methods of producing(a) Polymerisation (b) Fischer– Tropsch process(c) Bergius Process

1. 3. Synthetic fuel or synfuel is a liquid fuel obtained from coal, natural gas, oil shale, or biomass.It may also refer to fuels derived from other solids such as plastics or rubber waste. It may also (less often) reerto gaseous fuels produced in a similar way.Common use of the term "synthetic fuel" is to describefuels manufactured via Fischer Tropsc hconversion, methanol to gasoline conversion, ordirect coal liquefaction.
2. 4. Methods of producing synthetic petrol:• Polymerisation• Fischer- Tropsch method• Bergius process Poiymerisation:In this method, smaller molecules of hydrocarbons arecombined to form heavier molecule resembling gasoline.It is of two type:(a)Thermal polymerisation(b)Catalytic polymerisation
3. 5. (a)THERMAL POLYMERISATION:Thermal polymerisation is carried out at temperature about500-600 C and pressureabout 70-350 kg/cm.cm(b)CATAIYTIC POLYMERISATION:It is carried out at a lower temperature of 150-200 C ,in alow pressure and in presence of catalyst like posphoricacid. The rate of reaction is increased. The gasolineobtained is of improved quality andpossess high antiknock properties than the gasolin eobtained from thermal polymerisation process.
4. 6. The Fischer– Tropsch process (or Fischer– Tropsch synthesis) is acollection of chemical reactions that converts a mixture of carbonmonoxide and hydrogen into liquid hydrocarbons. The process, akey component of gas to liquids technology, produces a synthetic lubrication oil and synthetic fuel, typically from coal, natural gas,or biomass.[1] The F–T process has received intermittent attentionas a source of low-sulfur diesel fuel and to address the supply orcost of petroleum-derived hydrocarbons.
5. 7. Fischer- Tropsch processThe water gas is varied with hydrogen and the combination is purifiedby transitory from side to side Fe2O3 and then into a mixture ofFe2O3+Na2CO3. The cleanse gas is dense to 5 to 25 atm and then led fromside to side a converter, which is preserve at a temperature of 200 –300oC.The converter is provided with a catalyst bed consisting of amixture of 100 parts cobalt, 5 parts thoria, 8 parts magnesia and 200parts keiselghur earth.The outcoming gaseous mixture is led to a condenser, where theliquid crude oil is obtained. The crude oil is fractionated to yield gasolineand heavy oil. The heavy oil is used for cracking to get more gasoline.
6. 8. :Bergius processOne of the main methods of direct conversion of coal to liquids by hydrogenation process is the Bergius process.In this process, coal is liquefied by mixing it with hydrogengas and heating the system (hydrogenation). Dry coal ismixed with heavy oil recycled from the process. Catalyst istypically added to the mixture. The reaction occurs atbetween 400 °C (752 °F) to 5,000 °C (9,030 °F)and 20 to70 MPa hydrogen pressure. The reaction can be summarizedas follows:
7. 9. Bergius Process - Synthetic Petrol:In this process, the finely powdered coal is completed keen on a paste throughheavy oil and a catalyst powder (tin or nickel oleate) is mixed with it. The paste ispumped along with hydrogen gas into the converter, where the synthetic paste is heatedto 400 - 450°C under a pressure of 200 - 250 atm.During this process hydrogen combines with coal to form saturated higherhydrocarbons, which experience additional decay at superior temperature to acquiescecombination of lesser hydrocarbons. The mix is led to a condenser, where the crude oilis attained. The crude oil is then fractionated to yield:(a)Gasoline (b)Middle oil (c)Heavy oil